The Turkish gardener who allegedly shot three generations of the same British family did so because of an argument over his secret relationship with the woman who died, his parents have said.

Veli Acar, 46, has been arrested on suspicion of murdering Catherine Anne Bury by shooting her four times with a pump-action shotgun, as well as firing upon and injuring her 24-year-old son Alex, and her 87-year-old mother Cecille.

According to Mr Acar’s father Dursan, 77, an argument started at Ms Bury’s 56th birthday party because Alex questioned why the gardener was present, telling him to leave.

Reports have surfaced that Mr Acar and Ms Bury were in a long term relationship, and after handing himself in the suspect is said to have told Turkish police the shootings were “a crime of passion”.

But the Bury family deny the existence of any such romantic attachment – and Dursan Acar says the fact that it was a secret is what ultimately led to Ms Bury’s tragic death.

Speaking to The Times yesterday, the gardener’s father said the couple were not married but “they lived like man and wife”.

He said: “Alex did not know about the relationship. It got to the end of the party, and he said ‘why is the gardener still here, f**ck off’.”

Ms Bury’s mother and her brothers have consistently denied that she had been seeing Mr Acar, calling the claims made by his family “completely untrue”.

They said a dispute with the gardener, which led them to lodge a complaint about him with the police days before the shooting, came about because Ms Bury confronted him over money he took which should have been passed on to other local tradesmen.

In a statement the family said: “It appears that the person that Anne employed as a general gardener/handyman, to look after her holiday villas, has committed this terrible crime . . . We cannot comprehend the mentality of somebody who would do this to three lovely people who would never harm anybody.”

The Turkish Ministry of Culture and Tourism said in a statement: “The death of British citizen (Catherine) Anne Bury, and the wounding by shooting of her son, Alexander Gerard Bury, and mother, Cecilia Bury, in Turkey's south-western town of Dalyan is currently being investigated by the relevant authorities.

“The chief suspect has been arrested and is currently under custody, while a full investigation is under way.”